Mathematics, 07.10.2020 23:01 Shubbs

According to a survey by Bankrate, of adults in the United States save nothing for retirement (CNBC website). Suppose that adults in the United States are selected randomly. a. Is the selection of the adults a binomial experiment? Explain. The selection - Select your answer - a binomial experiment because the adults are selected - Select your answer - , - Select your answer - from trial to trial, the trials - Select your answer - independent, and there are - Select your answer - outcomes possible. b. What is the probability that all of the selected adults save nothing for retirement (to 4 decimals)? c. What is the probability that exactly five of the selected adults save nothing for retirement (to 4 decimals)? d. What is the probability that at least one of the selected adults saves nothing for retirement (to 4 decimals)?

Answers: 1

Show answers

Answers

Answer from: martinezlittleman

Complete Question

The complete question is shown on the first uploaded image

Yes the selection of 15 is a binomial experiment

$P(r = 15) = 3.2768 *10^{-11}$

P(r = 5) = 0.1032

$P(r \ge 1 ) = 0.9648$

Step-by-step explanation:

considering question a

Generally for and experiment to be binomial

The trial must be independent

There must be only two outcomes for each trial

Generally given that that the 15 adults are selected randomly which mean that the trials will be independent and that desired outcome is ''ether the adult save something for retirement or the adult saves nothing for retirement ''

Then we can say that the selection of 15 adult at is a binomial experiment

Considering question b

Generally the probability that all of the adults save nothing for retirement is mathematically represented as

$P(r = n) = ^nC_r * p^r * q^{n-r}$

Here C stands for combination

r = 15 i.e all the selected adults

n is the sample size with value 15

From the question p = 0.20

and q is calculated as

q = 1 - p

=> q = 1 - 0.20

=> q = 0.80

$P(r = 15) = ^{15}C_{15} * p^{15} * q^{15-15}$

$P(r = 15) = 3.2768 *10^{-11}$

Considering question c

Generally the probability that exactly five of the selected adults save nothing for retirement is mathematically represented as

$P(r = 5) = ^{15} C_5 * (0.20)^5 * (0.80)^{15}$

P(r = 5) = 0.1032

Considering question d

Generally the probability that at least one of the selected adults saves nothing for retirement is mathematically represented as

$P(r \ge 1 ) = 1 - P (r = 0 )$

$P(r \ge 1 ) = 1 - [ ^{15} C _ 0 * (0.20)^{0} * (0.80 )^{15}]$

$P(r \ge 1 ) = 1 - 0.0352$

$P(r \ge 1 ) = 0.9648$

Answer from: Quest

for the friend request.

when a figure, such as triangle (xyz) is reflected over the line y = x to create x'y'z' the x-coordinates and y-coordinates of the original image (pre-image) will be reversed for the image. (e.g., (x, y) > (y, x)) this means that the pre-image position of the x- and y-coordinates switch places which in turn provides a mirror like image of the original xyz.

i notice that when i draw a line segment from x to x', that the points are parallel from each other -- they are exactly across from each other and do not intersect with any other points.

yes, think i would see the same characteristic if you drew the line segment connecting y with the reflecting line and then y' with the reflecting line because of the essence of reflections. because it is a mirror image, each point was effected the same way which leads me to conclude that they same would apply to y and y'.

Answer from: Quest

according to the triangle sum theorem, all the angles in a triangle must add up to 180 degrees. if we know one angle is already 90, we do 180-90=90. the other 2 angles must add up to 90, exactly.

step-by-step explanation: